This may be a few months late (I've just signed up here), but it may concern others trying for similar results (including myself, most likely, once I get to ordering my first print). As an alternative to the worrying-sounding superglue method, have you tried using Future/Klear/Pledge etc. acrylic floor polish? It's commonly used by modellers as a fairly hard-wearing varnish, is completely clear and is about as fluid as pure water.
You could spray it on, or possibly even quickly dip it.

Obviously I haven't tested it myself yet, at least not for this material (though it's done a fine job when brushed onto papier maché models), but it's something to consider.

I've finally ordered my first models today. When they arrive in a week or so, as well as seeing if the models themselves work as I intend, I'll also be testing my Klear on them.

The theory is that the WSF should nicely absorb my paint, and then a few coats of Klear will hopefully a) seal the paintjob, b) toughen up the WSF, and c) smooth the surface somewhat and offer a bit of a sheen.

Quick update with this. My prints arrived today, and I've started testing my theories on my Blazer head. So far it's absorbed about three coats of thinned red acrylic quite nicely (the first coat watered down quite a lot just to tint it, then a couple of coats roughly the consistency of milk). This alone has made the details stand out much better.

I've washed half the head (the front) with a coat of Klear so far, and it looks nicer already. Once that coat's dried and I've done the same to the back, I'll snap some shots to show you how it looks so far. I plan to do any detail painting over the top of the basic Klear coat, then add more varnish over that.

Here's how the head looked a little while ago. As I said, this is after about three thinned coats of paint and one all-over coat of Klear.
Since then I've added another final coat of paint (undiluted, including paint apps for the eyes), and I'm just topping it up with varnish now.

I've tried the sealer from "DecoArt DASK282 Americana Finishes Sample Pack". It seemed to be perfect for WSF and it's clear so no danger of it soaking colour through to a different part of the model (as dilute paint can sortof wick through the model). The other finishes in that pack seem to work really well too and the variety is good.

Hi, I'm using ProFix CM10 Matt 2 component clear coat, on WSF polished which I dyed black myself, but it's very difficult to get a consistent result. I'm applying it with a spray gun. It's a 2:1 mix with a 10% thinner.

First time I tried it, I got a really nice smooth coating.
Second time it turned out like sandpaper.

The difference I could think of was the temperature and flash time between coats. I did 3 coats, but the first time it was around 20-25C and 5 minutes between coats. On the 2nd time it was about 30C and 10-15 minutes between coats. The pressure meter isn't very accurate, although I think I was trying a higher pressure with lower flow on the second time. The first time had a pretty high flow.

Any ideas what I can do?

The parts need to be scratch resistant, which is why I'm using 2K coats. Any recommendations on something different?